A new water soluble complex, W(CO)(3)(CH3CN)(TPPTS)(2), has been synthesized by the reaction of the water soluble ligand tris-meta-sulfonato-phenylphosphine (TPPTS) with the tungsten precursor W(CO)3(CH3CN)3 and characterized using spectroscopic techniques. The new complex shows high solubility and stability in water demonstrated by UV-VIS studies. This complex is an effective catalyst precursor for the liquid-biphase hydrogenation of the double bond in the presence of surface active agent like cetyltrimethylammonium chloride (CTAC) of various alkenes such as 1-hexene, 1-decene, allylbenzene, styrene, 1-cyclohexene and 1-methyl-1-cyclohexene. The activity of this complex has an influence depending of the type substrate used and with this ligand, it remains as a molecular complex, independently of the reaction condition used. At the end of the reaction, all the metal remains in the aqueous phase without indication of partition of the complex towards the organic phase. (C) 2002 Elsevier Science B.V. All rights reserved.